The PL-131C CoolAir fan-cooled camera offers exceptional performance
and versatility easily outperforming cameras costing considerably more.
The camera excels as a planetary (Solar and Lunar) camera with frame
rates of up to 220fps. It is also ideal as a guider or for industrial
inspection and microscopy applications. Gain, Region of Interest (ROI)
and binning are all features implemented in the hardware to deliver
exceptional performance.

The PL-131C camera has been designed to deliver high image quality at
unusually high frame rates. The camera is capable of capturing an image
even at a minimum 1ms exposure (10secs max in single shot mode) at all
supported resolutions and with frame rates of up to 220fps.

The PL-131C camera requires a fully featured, full speed USB2.0 port to
take advantage of all the camera’s advanced features. Please refer to
Hardware Requirements lower in the page for more information and advice.

Region of Interest – ROI

ROI has been implemented in hardware and offers fast frame rates at the
expense of field of view. Frame rates of up to 220 frames per second are
possible. In addition the position of the ROI window can be set by the
user via the supplied software and repositioned as required.

The above example shows the ROI in action. The user can resize (1280x1024,
640x480, 320x240) and reposition the ROI over the planet in this example so
as to dramatically increase frame rates from 22fps to 80fps and to 220fps
respectively without reducing the actual size of the planet, this remains
the same in all three images i.e. 306x204 pixels approximately. In practice
the ROI reveals and sends to the computer only a portion of the total sensor
area.

As such considerable amounts of detail can captured at these extreme speeds.
The size of single frames and video files are also greatly reduced resulting
in singe frames and AVI video files of 1/4 and 1/16 in size without
compromising image quality.

R.O.I. Size(in pixels)

R.O.I. Position

Frame Rate *

Frame Size(megapixels)

1000 framesAVI File Size

Total Time for1000 Frames*

1280x1024

whole sensor area

22fps

1.3mp

1300 MB

46 seconds

640x480

user definable x, y

80fps

0.325mp

325 MB

12.5 seconds

320x240

user definable x, y

220fps

0.081mp

81 MB

4.6 seconds

* maximum (depends on computer hardware & assumes 1ms exposure time).

Binning Modes

Binning is implemented in the camera hardware for improved performance
and is useful when you need to increase the camera’s light sensitivity.
Binning increases light sensitivity at the expense of resolution, the
field of view remains the same in all binning modes. The camera uses
the whole of the sensor surface to collect photons and outputs the image
at different resolutions depending on the binning mode selected. The
diagram below is for illustration purposes and shows the effect of
binning as light sensitivity increases and resolution/image size
decreases, exposure time remains the same.

Binning Mode

Resolution

Sensitivity

Binning

Frame Rate

1x1

1280x1024

x1

not applicable

22fps

2x2

640x480

x4

hardware

80fps

4x4

320x240

x16*

hardware/software

80fps

* maximum

Hardware Gain

Gain is implemented in the camera hardware and is useful in amplifying
the incoming signal. This feature is particularly useful when minimum
exposure times and/or maximum signal levels are required.

Planetary, Lunar and Solar Imaging

When imaging the Sun, Moon and planets atmospheric turbulence will have
an adverse effect on the quality of the image. As such the best way to
capture a high quality image of say a planet is by capturing hundreds
or thousands of frames in succession and in the minimum amount of time
possible. The resultant AVI video file can then be imported in say
AstroArt or the freely available Registax where the image frames can be
stacked by the software in a single final image of superior quality.

At a maximum frame rate of 220fps the PL-131C CoolAir is the ideal
planetary and Lunar camera offering high quality video streams while
dramatically reducing hard disk space requirements and the size of
captured video AVI files.

For planetary imaging we recommend running the camera at 1280x1024 with
the ROI set at 320x240. This ensures the highest image quality at the
highest speeds possible, i.e. 220fps. When long focal lengths are used
(i.e. over 6 meters for the larger planets) the camera ROI can be set
to 640x480 (80fps) to comfortably fit the planetary disk inside the ROI
window.

The 1/2" format sensor will accommodate focal lengths of around 12 meters
for the largest planets so that the projected planetary disk remains
smaller than the size of sensor. If the focal length used is around 12
meters you would use the camera at full resolution (22fps, ROI set to OFF).

For Lunar imaging setting the camera at 1280x1024 and the ROI at 320x240
will suit smaller Lunar features and/or when you want to draw out that extra
detail. Otherwise for medium sized Lunar features running the camera at
1280x1024 with the ROI set at 640x480 will offer the best option. If you
are interested in capturing as much of the area of the Moon as possible in
a single shot you will need to run the camera at its full 1280x1024 resolution
at 22fps (ROI set to OFF). What applies to the Moon also applies to the Sun
(full aperture Solar filter required).

Finally the camera’s high speed makes it ideal for imaging (and viewing) in
real time ‘fast moving’ targets like the International Space Station.

Auto-guiding

The PL-131C CoolAir camera can be used as a guide camera and offers a
number of features useful in auto-guiding sometimes not found in dedicated
guiding cameras.

Hardware binning allows your guide camera to reveal and guide on fainter stars.
Its ability to bin makes it ideal for guide scopes with shorter and longer
focal lengths as you can better match the guider scope’s focal length to the
size of the pixels. An on-board camera frame store ensures the highest
image quality and S/N ratios.

The camera needs an auto-guide controller like the Shoestring GPUSB
unit to be able to auto-guide with any ST-4 compatible mount. The Opticstar AG-131C CoolAir
is the auto-guiding version of the PL-131C CoolAir and includes the PL-131C CoolAir
camera as well as the Shoestring GPUSB unit.

Other Applications

The PL-131C CoolAir is very well suited to microscopy and machine inspection in
particular due to its high frame rates combined with high image quality. The
camera will perform well even under not ideal lighting conditions.

Hardware Requirements

The PL-131C CoolAir camera requires a fully featured, full speed USB2.0 port to take
advantage of all the camera’s advanced features. Fully featured USB2.0 ports
are rare in older laptops and not always present in entry level laptops.
PCMCIA/CardBus USB2.0 cards typically do not deliver full USB2.0 speeds and
will not work with USB2.0 high resolution video cameras including the PL-131C CoolAir.

To resolve such issues an ExpressCard (with a USB2.0 port) could be
used instead of a PCMCIA/CardBus card due to the ExpressCard's
superior speed of 2.5Gbit/s (480 Mbit/s through USB 2.0) per slot.

Express type cards use a 34mm slot where PCMCIA/CardBus cards use
54mm slots. An ExpressCard should be connected directly to the
computer and not via a PCMCIA/CardBus card.

Please note the ExpressCards will resolve USB related issues assuming
that the laptop data bus can support full ExpressCard speeds and is
fully implemented.

The cooling mechanism.

Computers with slower USB2.0 ports may still be able to capture at
full resolution but may be able to only transfer a user selectable
area (ROI 640x480 or 320x240) to the computer while sustaining image
resolution and high frame rates. This does not have a real effect
when imaging planets where video capture should ideally take place
at the smallest ROI size possible, typically 320x240 @ 220fps for
focal lengths to around 6 meters for planets like Jupiter or Saturn.

Always download and install the latest Windows and Direct X service
packs.

This does not have a real affect when imaging planets where video capture should ideally
take place at the smallest ROI size possible, typically 320x240 @ 220fps for focal
lengths to around 6 meters for planets like Jupiter or Saturn.

Options

Optionally, the PL-131C COOLAIR incorporates a removable x0.5 focal reducer nosepiece that can double
the field of view if required. An extension 5 metre USB lead with a USB repeater (amplifier)
is also available in cases where the camera will be used further away from the computer.

The camera comes with a C/CS ring and a 1.25" telescope adaptor threaded for filters.
A C/CS to T-thread adaptor is available as an optional extra. The camera will accept
standard C and CS mount lenses as well as T-thread lenses (with the optional adapter).
The PL-131C COOLAIR can also be mounted on standard photographic tripods as it incorporates
a 1/4" photographic female thread.

In addition to EMAMCAP, the camera is bundled with a number of software applications
including Craterlet, Nebulosity Lite, PHD Guiding and Guidemaster. Also there are
software plug-ins for third party applications such as AstroArt and MaxIm DL. The
most appropriate software to use depends on the particular application.

If maximum frame rates are required then the camera should be configured as a
Windows DirectShow/WDM device. Alternatively, if maximum light sensitivity is desired
then it should be used in native mode.

The PL-131C COOLAIR is supported natively in Nebulosity, PHD Guiding, AstroArt and MaxIm DL.
The camera can also be used as DirectShow/WDM video camera in Craterlet, PHD Guiding,
Guidemaster, EMAMCAP, AstroArt and MaxIm DL.

Craterlet Software

Craterlet is a capture application for video cameras compatible with Windows
DirectX (DirectShow) and WDM. It provides streaming to AVI, still capture and a simple
but clean interface. Streams to AVI format at ~30 FPS, ready for processing in other
software such as Nebulosity. It can quickly cycle among the camera's modes and allows
the user to specify frame rate and capture duration. It is able to capture individual
still frames in BMP format. Craterlet is ideal when high frame rates are desirable.

Nebulosity Lite Software

Nebulosity is a fully featured, but simple to use capture and processing application.
Astronomy images from just about anything can be processed (support for many FITS formats,
PNG, TIFF, JPEG, CR2/CRW, etc). Nebulosity Lite is bundled with the camera and it supports
lapse photography, 1x1 and 2x2 binning modes, StarView real-time video preview mode,
region of interest, frame stacking, support for all popular file formats and more.
This should be the application of choice over etAMCAP or Craterlet when high sensitivity
is required rather than high frame rates.

PHD Guiding Software

PHD Guiding is designed to be simple, yet provide powerful, intelligent auto-guiding
of your telescope. Connect your mount, your camera, select a star, and start guiding.
That's it! In PHD Guiding, all calibration is taken care of automatically. The camera
can be used with PHD Guiding in Windows DirectShow/WDM mode when exposures of under
half a second are required, or in native PL-131 mode for exposures of over 500 milliseconds.
Longer exposures increase the camera’s sensitivity.

Guidemaster Software

Guidemaster can be used as an alternative to PHD Guiding. Please note that there is no
support for longer exposures for the PL-131 in Guidemaster. Therefore PHD Guiding
(or AstroArt or MaxIm DL) will perform better because of the longer exposure times.

Image Quality

The ability of the camera to capture and store high quality video to disk in real-time provides
the data required for stacking any number of frames to create a single greatly enhanced quality
image using image stacking software, these include Nebulosity (bundled with the camera),
the excellent AstroArt, the freely available
Registax and others.